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United States Department of Agriculture

Agricultural Research Service

Research Project: KARNAL BUNT COOPERATIVE RESEARCH
2011 Annual Report


1a.Objectives (from AD-416)
The objectives of this cooperative research are:.
1)develop and test wheat lines with resistance to KB; and.
2)develop and test molecular markers for resistance to KB.


1b.Approach (from AD-416)
Wheat experimental lines have been developed by crossing adapted varieties with different sources of resistance to KB. Wheat lines will be tested for resistance to KB in the field in India. Genetic mapping populations and near isogenic lines will be developed to identify and validate molecular markers for KB resistance genes. Molecular marker genotyping will be done in India and the USA. Data will be analyzed cooperatively.


3.Progress Report

Hard red or white winter wheats were inoculated with sporidial suspensions derived from a mixture of isolates of the Karnal Bunt pathogen (Tilletia indica) by the syringe inoculation method under field conditions in Ludhiana, Punjab, India. The 4th, 5th, 6th, 7th, and 8th Winter Wheat Karnal Bunt Screening Nurseries (WWKBSN) were vernalized and planted in October, 2010. All the lines were inoculated at the appropriate stage, i.e. at awn emergence. Frequent irrigation was carried out to maintain adequate humidity for disease development. Plants were scored in March-April, 2011. Disease pressure was uniformly high and results were consistent between replications.

Many wheat lines that showed resistance in previous years again showed moderate to good resistance. A set of progeny from the cross between HD29 (resistant Indian spring wheat variety) and Jagger (susceptible Kansas winter wheat variety) showed several fixed lines with good resistance. Likewise, progeny from a cross between a resistant synthetic spring wheat and Karl 92 (susceptible Kansas winter type) continued to show moderate resistance. A new doubled haploid mapping population between a source of very high resistance and a susceptible line was evaluated for the third year. This population will be genotyped in the coming year. A backcrossing program using Jagger as the recurrent parent is at the third backcross generation. One more year of testing is needed to validate the resistance in these lines.

Progress on this agreement is monitored by regularly discussing program goals, approaches, and results (teleconference, email) and by reviewing annual accomplishments reports.


Last Modified: 11/26/2014
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